JPH1037055A - Composite nonwoven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composite nonwoven fabric having better bending resistance, water absorbency, soft touch feeling and tensile strength than those of a conventional composite nonwoven fabric using cuprammonium rayon filament yarns. SOLUTION: This composite nonwoven fabric is obtained by laminating a regenerated fiber web formed by using continuous filament yarns comprising Lyocell (R) fibers onto at least one surface of a synthetic fiber web formed by using synthetic continuous fiber filament yarns, interlacing and integrating the resultant laminate with a high-pressure water stream. At this time, the Young's modulus of the continuous filament yarns comprising the Lyocell (R) fibers when wetted is preferably 20-50kg/mm<2> .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an improved composite nonwoven fabric. More specifically, the present invention relates to a composite nonwoven fabric in which the web made of synthetic long fiber filaments and the web made of long fiber filaments made of lyocell fiber are entangled and integrated to improve feeling and water absorption.

[0002]

2. Description of the Related Art A non-woven fabric comprising synthetic filament fibers obtained by forming a heat-sealed portion having an embossed pattern or forming a heat-sealed portion by a flat heat roll and bonding and fixing the constituent filaments at the heat-sealed portion. Are known. Since these nonwoven fabrics do not require a binder, they have the advantage of lower production cost and do not contain impurities such as binders as compared with the method of bonding using a binder. It has the feature that there is no drop of lint as compared with a non-woven fabric using fibers.

[0003] However, the nonwoven fabric obtained by such a heat fusion method cannot obtain sufficient strength when the heat fusion point is small or not at all, and the strength is improved when the heat fusion point is increased. However, there is a drawback that the heat-fused point becomes a film-like portion, so that the feeling is impaired, the flexibility is lost, and a paper-like is formed. Further, when the nonwoven fabric is composed of 100% synthetic fibers, the water absorption is poor, and there is a limit to the application to clothing and wipers.

In order to solve such problems of the conventional nonwoven fabric, Japanese Patent Laid-Open Publication No. 1-139852 discloses a nonwoven fabric comprising two or more fiber layers using synthetic filament fibers and recycled filament fibers. Thus, a composite nonwoven fabric has been proposed in which the fibers of one of the two fiber layers penetrate into the other fiber layer and are entangled to join the two layers.

[0005] The recycled long fiber filament used in the known two-layer nonwoven fabric is a cuprammonium rayon or a visco rayon, and is hydrophilic and has a large decrease in Young's modulus when wet. When entangled in a high-pressure water stream, the fibers tend to move easily, giving the effect of being strongly entangled with the synthetic fibers, but the fibers are difficult to move with each other, and the texture after drying tends to be paper-like. There is
A satisfactory feeling has not yet been obtained for use in clothing. As for the water absorption, this composite nonwoven fabric is superior in water absorption to a nonwoven fabric of 100% synthetic fiber, but has not been satisfactory for wiper applications.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems of such a composite non-woven fabric comprising long fiber filaments and to impair the advantages of a non-binder and non-woven fabric comprising long fiber filaments. In addition, an object of the present invention is to provide a composite nonwoven fabric having good feeling and excellent water absorption.

[0007]

As a result of various studies on the above-mentioned problems, the present inventor has found that the above-mentioned entanglement and integration of a web composed of synthetic filament fibers and a web composed of filament fibers composed of lyocell fibers are performed. The inventors have found that the problem can be solved, and have completed the present invention.
That is, the present invention provides: A web formed by using a regenerated cellulose filament fiber composed of lyocell fiber is laminated on at least one surface of a synthetic fiber web formed by using a synthetic fiber filament, and is entangled and integrated by a high-pressure water flow. To provide a composite nonwoven fabric. It is also characterized in that the regenerated cellulose filament fibers composed of lyocell fibers have a wet Young's modulus of 20 to 50 kg / mm ² . The present invention also includes the following embodiments. (1) The jet pressure of the high-pressure water stream for entanglement and integration of the fiber web is 15 kg / cm ² or more,
The composite nonwoven fabric according to claim 1.

Hereinafter, the present invention will be described in detail. (A) Characteristics of composite nonwoven fabric: In the composite nonwoven fabric of the present invention, it is important to use a regenerated cellulose long fiber made of lyocell fiber. The regenerated cellulose long fiber composed of the lyocell fiber has different properties from known copper ammonia rayon or visco rayon as described later. That is, it has characteristics such as a high Young's modulus when wet or dry, a small degree of water swelling, and a fiber surface that is easily fibrillated by high-pressure water flow.
Due to these characteristics, a composite nonwoven fabric formed by using a regenerated long fiber filament made of lyocell fiber exhibits the following characteristics that are not present in a conventional composite nonwoven fabric.

When the nonwoven fabric of the present invention is entangled and integrated with a synthetic fiber web (hereinafter abbreviated as synthetic fiber web) layer by a high-pressure water stream, the conventional regenerated fiber cellulose is hydrophilic and has a Young's modulus when wet. Extremely lower, it is easy to move between the synthetic fibers and exerts the effect of being strongly entangled with the synthetic fibers, whereas when regenerated cellulose long fibers composed of lyocell fibers are used, the Young's modulus when wet is used. It is difficult to bend and the movement between the synthetic fibers is small, and the entanglement of the fibers with the synthetic fibers becomes gentle.

[0010] Accordingly, it was expected that the tensile strength of the formed composite nonwoven fabric was also lowered, but surprisingly, the tensile strength of the composite nonwoven fabric was evaluated. It has been found that it has a performance equal to or better than that. The reason is estimated as follows. In other words, countless fibrillated fibers are generated on the fiber surface by the high-pressure water flow due to the property of being easily fibrillated, and these fibrillated fibers are entangled with the synthetic fiber filaments as if they were plant hair roots, resulting in increased tensile strength. I think that the. In addition, since the entanglement between the synthetic fiber filament and the lyocell fiber filament is gentle, the feeling during drying is very soft. Furthermore, there are countless extra fine fibrillated fibers on the surface of this composite nonwoven fabric, and an effect of giving a very soft surface feeling can be obtained. It was also found that the presence of such a hydrophilic and ultrafine fibrillated fiber also exhibited excellent water absorption.

Hereinafter, the present invention will be described in more detail. (B) Synthetic fiber web: The synthetic filament fiber referred to in the present invention is obtained from a thermoplastic polymer such as polyamide, polyester, polyethylene, polypropylene and polyacryl, and may be a mixture thereof. The synthetic fiber web layer is a spunbond nonwoven fabric which forms a web by directly spinning these synthetic filament fibers on a conveyor by a melt spinning method, for example, and is partially fused.

The method of fusing is not particularly limited, but a heating embossing roll may be used, or a high frequency welder may be used.
Alternatively, an ultrasonic welder method may be used. It is sufficient that the fibers constituting the synthetic fiber web layer are organized to such an extent that they can be moved by the water flow, and the degree of fusion is not particularly limited. The single yarn fineness is not particularly limited, but is 5d or less, preferably 1.
0-3.0d is preferred.

(C) Lyocell fiber web: Lyocell fiber as used in the present invention means cellulose fiber obtained by spinning from an organic solvent. The regenerated cellulose long fiber comprising the lyocell fiber of the present invention is obtained by dissolving cellulose in an organic solvent that dissolves natural cellulose to form a cellulose solution, and wet spinning or dry spinning using this solution as a spinning solution. Cellulose fiber obtained by spinning.

The lyocell fiber has a Young's modulus of 2 when wet.
0 to 50 kg / mm ² , preferably 25 to 35 kg / m
m ² is desirable. When the Young's modulus is less than 20 kg / mm ² , movement of the filament under a high-pressure water flow is large, confounding becomes too large, and the feeling after drying becomes coarse and hard. On the other hand, if it exceeds 50 kg / mm ² , the hand becomes coarse due to the rigidity of the yarn itself, despite the lack of confounding.

The organic solvent may be a known solvent, for example, an amine oxide described in JP-B-60-28848, or may be another kind of solvent. In this case, the amine oxides used as the organic solvent include, for example, tertiary amine N-oxides (eg, trimethylamine, triethylamine, tripropylamine, monomethyldiethylamine, dimethylmonoethylamine, monomethyldipropylamine) Oxide of N-dimethyl-, N-diethyl-, N-dipropylcyclohexylamine; Oxide of pyridine; Cyclic mono (N-methylamine-N-oxide) such as N-methylmorpholine N-oxide. Among them, the use of N-methylmorpholine-N-oxide is preferred.

The lyocell fiber web of the present invention refers to a web mainly composed of lyocell fiber. Of course, 100% lyocell fiber is preferable. However, if the properties and functions of the lyocell fiber web can be exhibited, other regenerated cellulose fibers may be used.
For example, it may contain a small amount of a copper ammonia method rayon or a bisco rayon.

In the present invention, the regenerated cellulose long fibers mainly composed of spun lyocell fibers may be spread uniformly under running water as long fibers to form a sheet on a net. For example, spinnerets arranged in the direction of travel of the net conveyor and in the direction perpendicular thereto are used, and the spinning solution is discharged from the spinning hole and deposited on the net conveyor below from the lower end of the spinning bath. Alternatively, the net conveyor is advanced at a low speed, and a swinging device is used to give a predetermined pattern by oscillating in a horizontal direction perpendicular to the traveling direction of the net conveyor, and to give a certain overlap to unsolidified fibers. And stack.
Subsequently, the web formed on the net conveyor is subjected to scouring / washing processing in the process of moving the net conveyor, further subjected to water jet treatment to rearrange the fibers, and then dried to obtain a rolled lyocell fiber web. be able to.

(D) Composite nonwoven fabric: The method of joining the two kinds of laminated webs constituting the composite nonwoven fabric of the present invention, ie, the synthetic fiber web and the lyocell fiber web, can be carried out, for example, by the following method. The lyocell fiber web is superimposed on at least one surface of the synthetic fiber web and placed on a screen.
The screen is not particularly limited, and the material, mesh size, wire diameter, and the like can be freely selected according to the purpose and application. Then, a thin high-pressure water flow is applied from a number of nozzles, and at the same time, the pressure is reduced from the lower side to cause confounding.

The jet pressure of the high-pressure water stream is usually 15 kg /
cm ² or more, preferably 20 kg / cm ² or more, it is desirable that more preferably 30 to 50 kg / cm ² is used. If the ejection pressure is less than 15 kg / cm ² , fibrillation of the regenerated fiber web becomes insufficient, and entanglement between the fibers becomes insufficient, so that strength cannot be obtained.

The nozzle diameter used here is not particularly limited. The shape of the high-pressure water flow is not particularly limited, but a columnar flow is preferable from the viewpoint of energy efficiency. The reduced pressure is not particularly limited, but it is sufficient that the treated water is sucked to such an extent that the action of the high pressure water flow is not hindered. In some cases, this bonding process may be performed on both surfaces. The composite non-woven fabric thus obtained is further subjected to a hydrophilic processing,
It is also possible to perform secondary processing such as brushing.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described specifically by way of examples, but these do not limit the scope of the present invention. The evaluation of physical properties was performed by the following methods. (1) Tensile strength: evaluated according to JIS-1096. (2) Bending resistance: JIS-1096 (45 ° cantilever)
(3) Water absorption: JIS-1096 (evaluated by Vilec method)

(4) Hand feeling: The following two kinds of properties were evaluated as substitute properties using a hand feeling measuring device KES series manufactured by Kato Tech. (A) Compression characteristics (compression work, WC): KES-FB3
(Compression tester) (b) Surface characteristics (mean deviation of friction coefficient, MMD): KES
-FB4 (Surface testing machine) (5) Young's modulus: JIS-1013 (Initial tensile resistance test method)

(Example 1) A polyethylene terephthalate web obtained according to the method described in JP-B-48-3802 was used as a metal roll having an uneven pattern heated to a surface temperature of 130 ° C. A metal roll having a smooth surface heated to a temperature was passed through and partially joined to obtain a synthetic fiber web having a single yarn fineness of 2 denier and a basis weight of 30 g / m ² . Separately, pulp and N-morpholine-N- according to the production method described in JP-B-60-28848.
The aqueous oxide solution was put into a mixing tank and mixed under reduced pressure to prepare a cellulose spinning stock solution having a cellulose concentration of 10%. The cellulose stock solution was air-gap spun at a discharge temperature of 124 ° C. 1.5m spin hole of 0.8mm as spinneret
90 rows in the traveling direction and 1000 rows in the orthogonal direction on a 24-mesh net conveyor with m pitches were used. The spinning solution was discharged at a rate of 0.1 g / min per spinning hole, exited from the exit of the lower end of the spinning bath having a width of 5 mm, and was continuously collected on a net conveyor 50 cm below. The traveling speed of the net conveyor was 10 m / min, and a swing operation was performed 200 times / min using a swing device in a direction orthogonal to the traveling direction.

In a subsequent step, scouring and washing are performed, and a water jet treatment is performed to rearrange the fibers.
Thereafter, drying was carried out to obtain a lyocell fiber web having a basis weight of 20 g / m ^{2 and} a denier of 1.5 denier of a continuous fiber made of lyocell fiber. The lyocell fiber web was overlaid on the synthetic fiber web and guided on a 30-mesh screen moving at a speed of 2 m / min. 3 from above the screen
Water at a pressure of 5 kg / cm 2 was jetted from a 0.15 mmφ nozzle arranged at a density of 80 holes / cm, and at the same time, a vacuum suction treatment was performed at -50 mmHg from below. After the treatment, it was dried to obtain a composite nonwoven fabric.

(Comparative Example 1) A synthetic fiber web made of polyethylene phthalate and having a single-filament fineness of 2 denier and a basis weight of 30 g / m2 was obtained in the same manner as in Example 1. Separately from this, a copper ammonia rayon spinning stock solution is spun using a rectangular spinning funnel device capable of performing a downward tension spinning method, and a liquid containing a large number of filaments is fed from a lower slit of the spinning funnel device. The film is continuously collected on a net conveyor that travels down the membrane, subjected to a refining treatment in a subsequent advancing process, further subjected to a water jet treatment to rearrange the fibers, and then dried to obtain a copper ammonia resin. -20 g of basis weight consisting of 1.5 denier single yarn fineness of Yong continuous fiber
/ M ² of regenerated fiber web. A recycled fiber web was overlaid on a synthetic fiber web, and these two types of webs were used in Example 1.
In the same production method as described above, entanglement was performed with a high-pressure water stream to obtain a composite nonwoven fabric. Table 1 shows the evaluation results of the physical properties of Example 1 and Comparative Example 1.

[0026]

[Table 1]

As shown in Table 1, the long modulus filament of the lyocell fiber used in Example 1 had a Young's modulus of 31 kg / cm ² when wet, but the copper ammonia rayon used in Comparative Example 1 The wet Young's modulus of the filament was as low as 10 kg / cm ² . Comparing the other physical properties of the composite nonwoven fabric of Example 1 and Comparative Example 1, the softness (smaller values are softer), water absorption (larger values are easier to absorb water), The WC value (the smaller the value, the softer the hand), the MMD (the smaller the value, the better the slipperiness), and the tensile strength, which are the substitute characteristic values, are all composed of the lyocell fiber of the present invention, It can be seen that the composite nonwoven fabric using the regenerated long fiber filament having a Young's modulus of 20 to 50 kg / cm ² has excellent performance.

[0028]

According to the present invention, the composite nonwoven fabric using the long fiber filaments composed of lyocell fiber of the present invention has superior rigidity, water absorbency, and soft feeling compared to the composite nonwoven fabric using the conventional copper ammonia rayon filament. A composite nonwoven having tensile strength is provided. The composite nonwoven fabric having such excellent properties is suitably used for wipers, diapers, sanitary materials, and clothing.

Claims (2)

[Claims] 1. A web formed by using a regenerated cellulose filament fiber made of lyocell fiber is laminated on at least one surface of a synthetic fiber web formed by using a synthetic fiber filament, and entangled and integrated by high-pressure water flow. A composite nonwoven fabric, characterized in that: 2. A regenerated cellulose filament filament composed of lyocell fiber having a Young's modulus of 20 to 50 kg when wet.
^2. The composite nonwoven fabric according to claim 1, wherein